Upvote:2
I assume you will exit the airport, if so you need a visa as you are visa-free only if you stay inside the airport:
Question: I will be flying to Europe. I know that our aircraft will land in Δ°stanbul. I am not planning to leave the transit lounge. Do I need to get transit visa?
Answer: If you will not leave the transit lounge at the airport you are not required to have transit visa. Otherwise, you have to make visa application to the nearest Turkish Representation.
(Source)
If you need a visa, you can easily apply for an eVisa online.